Controller.



THORSTEN VON ZWEIGBERGK, OF PRESTON, ENGLAND.

CONTROLLER.

Specification of Letters Patent.

Patented July 30, 1907.

Application in November 2a, 1906. Serial No. 345.437.

To all whom it mayconcem:

. Be it known that I, Tnons'rEN VON Zwniennsex, a. citizen of the UnitedStates, residing at Preston, in the county of Lancaster, England, haveinvented a certain new and useful Improvement in Controllers,

of-which the following is a full, clear, and exact description,reference being had to the accompanying drawings. 1

The object of this invention is to provide a controller for a hoistingor elevator motor which shall automatically establish an electric brakeon lower ing, thereby insuring the motor from running away. I accomplishthis by providing a resistance which the controller establishes in shuntaround the armature in lowering positions, whereby the counter-electromotive-force increasingly developed by increasing speed of the armatureautomatically checks such armature, forming an electric brake andefliciently limiting the armature spee The invention is hereinafter morefully described and its essential characteristics summarized in theclaims.

The drawings are diagrams sufiiciently illustrating theinvention,-Figure 1 beinga development of the controller, and Fig. 2showing the circuits at successive lowering positions.

In the diagrams, the successive positions are indicated by numerals,there being five raising positions and six lowering positionsshown.

A single set of contact fingers is illustrated, and it is to beunderstood that the controller barrel is turned in one direction pastsaid fingers for raising and in the opposite direction for lowering.

The following reference characters are used.

S and S indicate the raising and lowering contact segments respectivelyand C the contact fingers.

A indicates the'armature; F thefield of the motor; '1 the source ofcurrent, and 'G the ground or return iine;R R R and R the successivesections of the main resistance and r, 1 ,1 the sections of the shuntrcsistance.

On the raising positions, the controller gives the usual resistancegovernment,in the first position connecting the motorfin series with"the entire resistance, and then. successively cutting outv resistanceuntil in the final position (No. 5) the resistance isentirely cut out.In lowering, the'armature is re versed. On the first position, theresistance is maintained in series with the field of armature and'an additional resistance r is established in a shunt around the armature. Onthe second notch, the resistance around the armature is increased, theshunt passing in series through the resistances r and r. 'Inthe thirdposition, the resistance is further increased,

the shunt passing through the three resistances 1",

ture in the first notch on the lowering side, the motor starts, as thefield is already excited to its full capacity and the armature starts bythe drop in the voltage across the resistance shunt. As soon as thearmature speeds up, the counter electro-motive force cuts down thecurrent in the armature, and actually reverses the current when thespeed is high enough to overcome the drop tending thereby to reduce thespeed of the armature. Then as the controller is moved to the secondnotch, the armature receives an increased speed, due to the increaseddrop in the resistance shunt which is again counterbalanced by theincreased counter electro-motive force. On the third position, the stillhigher and again'receives a check by the counter electro-motive forcedeveloped. There is a reversed current flowing on each of the 3 firstnotches, due to the generative action of the motor as soon as thecounter electro-motive force has reached a higher value than the drop inthe shunt When it is desired to lower at full speed, the controller isturned successively through positions N o. 4, 5 and 6 which cut out themain resistances. If the motor tends to run away due to the increasedmomentum of the falling load, on the 3 last notches it is only necessaryto throw the controller back onto the third lowering notch whichestablishes the armature shunt wherein the reversed current will causean-efiective brake.

With my controller, it is possible to efiiciently and safely operate ahoist without the necessity of constantly shutting off the controllerand applying a hand brake when the speed exceeds the safe limit. Theelectric brake is entirely automatic on the first notches in lowering,and insures against any runningaway. I

Having thus described my invention, I claim:

1. A controller for a hoisting motor having raising positions adapted togovern the motor and lowering positions adapted to reverse the motor andestablish a. resistance shunt about the armature with the source ofcurrent.

2. A controller for a hoisting motor. having means for reversing themotor and automatically establishing an electric brake for such reversedmotor whereby the load may be lowered under control. 1

3. A controller for a hoisting motor having raising posi' tlons adaptedto successively cut out resistance and successive lowering positionsadapted to maintain connection with the source of current and alsoestablisha shunt around the armature and thereafter open such shunt.

4. In a controller, the combination or contact members arranged toautomatically establishresistance in increasarmature speeds whilemaintaining connection ing amount in 'a shunt around the armature whilemaintaining connection with the source of current for successivetroller, and then to open the shunt and finally to govern the field withsaid shunt open,

T. A controller for a hoisting motor having raising positions adapted tosuccessively cut our. resistance and iower= ing. positions adapted,while the source of current is connected, to reverse the motor andconcurrently establish a. resistance shunt around the armature andthereafter open such shunt and cut out the governing resistance.

8. The combination withi-a motor and. resistance in series with itsfield ot a control-Jeri having contact members arranged to cut out suchresistance for raising and arranged to automatically establish otherresistance in a shunt around the armature in increasing amount forsuccessive lowering positionsof; the controller, and then to open theshunt and finally cut out the resistances in series withthe field.

9. The combination with a motor and a field resistance, of a secondresistance and a controller having positions which successivelyestablish the second resistance in increasing amount around thearmature, then open the shunt and cut out the resistance which was inseries withv the field.

10. A controller for a hoisting motor comprising contact fingers andcontact plates adapted to cooperate therewith. one set of such' platescorresponding to the elevating rotatiou of the motor, and the other tothe lowering rotation, a main. resistance, connections established bythe elevating side of the controller for successively cutting out suchresistance, a second: resistance,' and connections established by thelowering-side of the controlier for successively establishing suchsecond resistance in increasing amount in 5 the'presence of two a shuntaround the armature, then opening such shunt and: then successivelycutting out the main resistance.

' 11. A controller for a hoisting motor having raising positlons adaptedto connect the motorwith the source of current and. successively cut'out resistance, and having semen lowering positions adapted to maintainthe armature and field in connection with the source of current and withthe motor reversed; and to concurrently maintain a shunt cir- -cuitabout the armature through a resistance, such resistance being graduallyincreased and then the shunt circuit V opened for successive loweringpositions.

12. A controller for a hoisting motor having raising positions adaptedto govern the motor and having lowering shunt about the armature whilemaintaining connection- With the source of current, there beingsubsequent lowering positions which open such shunt.

14. The combination with the motor and resistance of a controller havingraising positions adapted to. cut out resistance, and lowering positionsadapted to reverseand short circuit the armature by a resistance shunt,and having a subsequent position adapted to open such shunt.

15. A controller for a hoisting motor having raising positions adaptedto govern the motor, and lowering positions adapted to reverse the fieldof the motor and establish a resistance shunt about the armaturethereof.

16. A controller fora hoisting'inotor' hm ing raising positions adaptedto govern the motor, and lowering positions. adapted to reverse thefield of the motor and concurrently establish a resistance shunt aboutthe armature, successive lowering positions increasing such resistanceand subsequently opening such shun-in v 17. The combination of a motorand resistance in series with its field, of a controller having raisingpositions adapted to successively cut out such resistance, and havinglowering positions adapted" to reverse the held of the motor andestablisha resistance shunt around the armature while maintaining aconnection from the armature to the source of current, successivelowering positions in- I creasing the resistance in such shunt, andsubsequently open-ing the shunt and cutting out the resistance in serieswith the field.

In testimony whereof, I hereunto affix my signature in witnesses.

I THORSTEN VON ZWEIGBERGK.

" Witnesses:

W1 J2, Sums, H. WATSON.

